Numerical Research On Flow And Heat Transfer Of The Third Fluid In Cooling Channel

In this paper,based on the design calculation of certain liquid rocket engine,a 2D and 3D numerical simulation were proceed to study the flow and heat transfer characteristics of the third fluid in the cooling channels.Taking the limiting temperature of the chamber and the outlet dryness of the third fluid as the limit,the inlet boundary conditions were obtained through the 2D simulation.The range of the inlet temperature was 300-400 K,and the flow rate was limited to 0.024-0.036kg/s.Then the 2D results served as the boundary of the 3D simulation.Finally,through the 3D simulation,the characteristics of the third fluid were calculated.The results were useful for the design of the third fluid cooling cycle and the design,manufacture and regenerative utilization of the liquid rocket.The maximum temperature and maximum heat flux located at the throat.Therefore,the throat became the critical of the cooling of the thrust chamber.The third fluid cooled the thrust chamber through the boiling heat transfer in the cooling channels.The phase change occurred around the throat,and the location of the boiling was influenced by the flow rate and the inlet temperature of the third fluid.The higher the flow rate was,the longer the distance to the inlet was.And the higher the inlet temperature was,the shorter the distance to the inlet was.In addition,the flow rate and the inlet temperature of the third also affected the outlet dryness,temperature of the thrust chamber and the pressure loss of the third fluid.The relationships among the characteristics were confirmed through the numerical simulation.The results show that when the mass flow of coolant raises by about 0.01kg/s,the wall temperature of thrust chamber and throat temperature decreases by about 9K and 15 K respectively,while the outlet dryness of the coolant decreases by about 0.011.The influence of inlet temperature is affected by the coolant flow,when the flow is smaller,the influence of the inlet temperature can be ignored,while the flow is larger,the dryness of coolant raises by about 0.009 with the increasing of inlet temperature by 10 K.The pressure loss of cooling channel raises by 54 kPa with the growing of coolant flow by 0.01kg/s,and it decreases by about 24 kPa with the raising of inlet-temperature by 10 K.